i:r, ANNUAL REPORT OP THE Off. Doc. 



venously 0.001 gramme of a sciaijiug from a serum culture of tubercle 

 bacilli dried in vacuum, powdered, aud suspended iu water. The 

 culture used for this purpose was obiaiued originally from human 

 sputum and has been grown in his laboratory since 1895. After 

 four weeks a second injection is made containing twenty-live times 

 the original quantity of tubercle bacilli, or 0.025 gramme. Von Beh- 

 riog has now underway extensive experiments planned to test the re- 

 sistauce of immunized calves to natural infection from association 

 with infected animals in contaminated premises. 



Since 1896 tuberculosis of cattle has been the subject of special 

 and extensive study and experimentation iu the laboratory and re- 

 search station of the Pennsylvania State Live Stock Sanitary Board. 

 During this time the viruleuce for cattle and other animals of tuber- 

 cle culture and material from many sources have been tested by Dr. 

 M. P. Ravenel, Dr. John J. Repp, and ourselves. The results of some 

 of this work have been reported upon several occasions to this Society 

 by Dr. Kavenel and to the British Congress on Tuberculosis iu 1901. 

 Some experiments looking toward the development of better methods 

 for repressing tuberculosis iu herds have been reported by Dr. 

 Leonard Pearson. 



It has been shown by numerous experiments that the sputum of 

 persons suffering from consumption aud cultures of tubercle bacilli 

 made from such sputum are usually comparatively non-virulent for 

 cattle. It is important to know, further, that a given culture of 

 sputum tubercle bacilli is incapable of producing serious disease in 

 such quantities as it may be necessary to use in an attempt to in- 

 crease an animal's resistance to tuberculosis. 



The following experiment throws light upon the question as to 

 the quantity of culture of this kind that may be administered and 

 the effect of repeated inoculations made in four ditierent ways. A 

 Jersey heifer (26415) shown by tuberculin test to be free from tuber- 

 culosis was inoculated iutraperitoneally September 29, 1900, with 

 4 c. c. of a standard suspension^ of human sputum culture that had 

 remained in a collodion capsule in the abdominal cavity of a bull for 

 seven months, and was then regained in pure culture by Dr. Ravenel. 

 The third generation on blood serum furnished the material for this 

 inoculation. The heifer was inoculated intravenously March 15, 1901, 

 with 13.5 c. e. of a standard suspension of tubercle bacilli, probably 

 of human origin, that had passed through a coati (Nasua narica), and 

 were recovered iu pure culture by Dr. Theobald Smith in 1895. This 

 culture had afterward remained about one year in a collodion capsule 

 in the peritoneal cavity of a heifer, had been recovered by Dr. Ravenel, 



IBy a standard suspension Is here meant a suspension of tubercle bacilli in water in such 

 quantity as to give an opacity equal to that of a twenty-four-hour culture of typhoid bacilli In 

 bouillon. 1 c.c. of such a suspension is estimated to contain the equivalent of 0.0O13 gramme of 

 tubercle bacilli after drying ten days in a desiccating chamber over calcium chloride. 



